It has values like W14,W15 etc. I wanted to increase the count by 1..i.e wanted to make it W15,W16 etc. But then I noticed that the update qry didn't work correctly. What I got as result was..W1,W1..etc.
The query I used :
UPDATE table_1 SET child_cd='W'||trim(CAST(SUBSTRING(child_cd FROM 2) AS INTEGER)+1)